A grinding machine for grinding discs is disclosed in WO97/48522 and incorporated herein by reference. WO97/48522 discloses use of a metal-bonded CBN or diamond wheel on a grinding machine to rough grind the edge of a disc, such as a semiconductor wafer, before use of a softer resin-bonded CBN wheel for finish grinding the disc edge and further describes an in situ technique for forming and re-forming a groove in the resin bonded CBN grinding wheel to grind the correct shape around the disc edge.
The machine also includes a small diameter grinding pin for grinding a notch of predetermined proportions around the edge of the ground disc.
The use of a resin-bonded CBN wheel for notch grinding has the disadvantage that such wheels are relatively soft compared with metal-bonded CBN or diamond wheels, and as such wear rapidly and need to be replaced frequently. Therefore such wheels have tended not to be used in such applications although the reduced damage to the workpiece resulting from the use of such wheels means that it is desirable if they could be used for notch grinding.
The present invention aims to provide a formable grinding pin for notch grinding which can be used for longer before it has to be replaced, and to a method of forming such a notch grinding pin and to an improved method of notch grinding.